The regions of Forlindon and Harlindon were inhabited by Elves and were the chief part of Gil-galad's kingdom, which extended, north of the Gulf of Lune, to include the lands east of the Blue Mountains and west of the River Lune as far as the inflow of the Little Lune. (Beyond that was Dwarf territory.) South of the Lune it had no clear bounds, but the Tower Hills (as they were later called) were maintained as an outpost....

The Peoples of Middle-Earth, HoME Vol 12, Part 2, Ch 10, Of Dwarves and Men: The Atani and their Languages

In Lindon north of the Lune [Forlindon] dwelt Gil-galad, last heir of the kings of the Noldor in exile. He was acknowledged as High King of the Elves of the West. In Lindon south of the Lune [Harlindon] dwelt for a time Celeborn, kinsman of Thingol; his wife was Galadriel, greatest of Elven women.

The Lord of the Rings, Appendix B, The Tale of Years: The Second Age

Gil-galad's people [in Forlindon] were mainly Noldorin; though in the Second Age the Elves of Harlindon were mainly Sindarin, and the region was a fief under the rule of Celeborn.

The Peoples of Middle-earth, HoME Vol 12, Part 2, Ch 10, Of Dwarves and Men: Notes, Note 65